1. Field of the Invention
The present disclosure relates to optical communication equipment and, more specifically but not exclusively, to wavelength-selective cross-connect switches and reconfigurable optical add/drop multiplexers.
2. Description of the Related Art
This section introduces aspects that may help facilitate a better understanding of the invention(s). Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
Wavelength-selective cross-connect (WSXC) switches and reconfigurable optical add/drop multiplexers (ROADMs) are important network elements in optical wavelength-division-multiplexing (WDM) networks because they can support dynamic provisioning and automated restoration in the network and can be implemented to be transparent to the signal bit rate, modulation format, and transmission protocol. Substantially the same physical-device architecture can be used to implement a WSXC switch and a ROADM, with the classification of the resulting physical device as the former or the latter depending mostly on the degree of switching enabled by the device. An optical-WDM network architecture employing WSXC devices has many attractive features that help to accelerate service deployment, accelerate rerouting around points of failure in the network, reduce capital and operating expenses for the service provider, and provide a network topology that is amenable to future network upgrades.
A conventional WSXC device typically comprises a plurality of individual constituent optical devices, such as de-multiplexers, switches, and multiplexers (MUXs), and numerous fiber connections between them. With the rapid growth of optical transport capacities, the number of constituent optical devices that are required to implement an adequate conventional WSXC device may be on the order of one hundred or more. As a result, conventional WSXC devices are disadvantageously facing many challenges, such as increased footprint, relatively high maintenance complexity and cost, and reduced reliability.